A cleaning solution for IC copper process after CMP and a preparation method thereof

Abstract

The application discloses a preparation method of a cleaning solution composition after IC copper process CMP, wherein the cleaning solution composition comprises: a surfactant, a wetting agent, an organic phosphine chelating agent, an organic amine chelating agent, a quaternary ammonium lye, an organic solvent, a defoaming agent, a pH regulator, and the rest is water; the quaternary ammonium lye is a THEMAH-containing composition directly prepared by the following method, which comprises: taking one or more of methylamine, methyl ethanolamine and methyl diethanolamine as one of raw materials, and reacting with ethylene oxide without a catalyst silica, and the reaction temperature is 20-100 DEG C. The application further discloses a preparation method of the quaternary ammonium lye. The application utilizes the characteristics of reaction self-heat release, is easier to control temperature, is convenient to operate, has lower energy consumption, has less by-products such as ethylene glycol in the product without using a catalyst such as silica, and can reduce the risk of ethylene oxide accumulation. The obtained quaternary ammonium lye containing THEMAH has component content ratios which can directly meet commonly recognized cleaning solution specifications.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing, specifically relating to a cleaning solution after CMP in IC copper manufacturing, a method for manufacturing the cleaning solution, and a method for preparing quaternary ammonium alkali solution in the cleaning solution. Background Technology

[0002] In the integrated circuit manufacturing process, with the rapid development of the integration density of very large-scale integrated circuits, the gate size is also shrinking rapidly. Damascus interconnect technology basically uses copper as the interconnect metal to achieve lower resistivity and RC delay, and its anti-electromigration performance is also much better than that of aluminum. At present, only the CMP process can achieve global planarization of copper interconnect technology. After the CMP process, the wafer surface will produce contaminants such as abrasive particles and organic residues due to the polishing slurry, which requires a post-cleaning process. Traditional copper CMP post-cleaning solutions are mainly acidic products such as hydrofluoric acid and citric acid. Although they can effectively remove contaminants, they will cause non-uniform corrosion on the copper surface after cleaning. Therefore, the research on alkaline cleaning solutions has become a development direction in the semiconductor industry.

[0003] During ultra-cleaning, the composition of the cleaning solution has a significant impact on cleaning efficiency and quality. Wet cleaning generally utilizes water-based liquids containing solvents, complexing agents, and surfactants. Through chemical actions such as corrosion and dissolution, combined with the mechanical action of a soft brush, contaminants on the wafer surface are removed. There are also reports of dilute hydrofluoric acid (HF), tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), ammonium hydroxide (NH4OH), and other strong acids, strong bases, and ozone water being used for post-CMP cleaning of Cu interconnects. However, most of these components are highly corrosive, easily causing increased surface roughness and excessive substrate loss after cleaning. Furthermore, some components are highly toxic (e.g., tetramethylammonium hydroxide), volatile, and highly irritating to human skin. Summary of the Invention

[0004] In view of all or part of the deficiencies of the prior art described above, the object of the present invention is to provide a method for preparing a cleaning solution composition after CMP in IC copper processing. This cleaning solution includes a quaternary ammonium alkali solution, with tris(2-hydroxyethyl)methylammonium hydroxide as the main component. Utilizing the exothermic nature of the reaction, temperature control is easier, operation is more convenient, and energy consumption is lower. Furthermore, without the use of catalysts such as silica, the product contains fewer byproducts such as ethylene glycol. In addition, it can reduce the risk of ethylene oxide accumulation, thus reducing safety risks. More importantly, the main objective of the present invention is not to increase the yield of the main component tris(2-hydroxyethyl)methylammonium hydroxide in the quaternary ammonium alkali solution, but to facilitate subsequent applications. The quaternary ammonium alkali solution directly obtained by the preparation method of the present invention directly meets the generally accepted specifications for alkaline substances in cleaning solutions in terms of the proportions of each component.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A method for preparing a cleaning solution composition after CMP in IC copper manufacturing, wherein the cleaning solution composition comprises: 0.01%–1% surfactant, 0.01%–0.5% wetting agent, 0.01%–2% organophosphorus chelating agent, 0.1%–5% organoamine chelating agent, 5%–10% quaternary ammonium alkali solution, 1%–15% organic solvent, 0.01%–0.1% defoamer, 0.5%–1.0% pH adjuster, and the balance being water, calculated by mass percentage; wherein the quaternary ammonium alkali solution is a composition containing tris(2-hydroxyethyl)methylammonium hydroxide directly prepared by the following method, which comprises: reacting ethylene oxide with one or more of methylamine, methylethanolamine, and methyldiethanolamine as raw materials in the absence of silica catalyst at a reaction temperature of 20–100°C.

[0007] The present invention also provides a method for preparing a quaternary ammonium alkali solution, the method comprising: using one or more of methylamine, methylethanolamine and methyldiethanolamine as raw materials, reacting with ethylene oxide at 20-100°C in the absence of a catalyst silica to obtain a quaternary ammonium alkali solution containing tris(2-hydroxyethyl)methylammonium hydroxide.

[0008] This invention uses one or more of the inexpensive and readily available methylamine, methylethanolamine, and methyldiethanolamine, along with ethylene oxide as reactants. It leverages the exothermic nature of the reaction, making temperature control easier, operation more convenient, and energy consumption lower. Furthermore, without the use of catalysts such as silica, the product contains fewer byproducts such as ethylene glycol, and this invention does not require any catalyst. In addition, the reaction rate of ethylene oxide is faster at 20℃-100℃ than at temperatures below 20℃, resulting in a lower risk of accumulation and thus a lower safety risk. The quaternary ammonium alkali solution obtained by the method described in this invention directly meets generally accepted cleaning solution specifications.

[0009] The methylamine is a gas, an aqueous solution, or an alcoholic solution; the ethylene oxide is a gas. The alcoholic solution of methylamine is a methylamine methanol solution or a methylamine ethanol solution, etc. In specific implementation, methylamine gas can be used for convenient transportation and production; it can be passed into water to obtain an aqueous methylamine solution.

[0010] When using methylamine, methylethanolamine, or methyldiethanolamine as a raw material, the molar ratio of methylamine to ethylene oxide is 1:2-5; the molar ratio of methylethanolamine to ethylene oxide is 1:1-5; and the molar ratio of methyldiethanolamine to ethylene oxide is 2:1-5. When using methylamine, methylethanolamine, or methyldiethanolamine alone, the molar ratio is as described above; if two or more of methylamine, methylethanolamine, and methyldiethanolamine are used, the molar ratio is adjusted accordingly. Excessive addition of ethylene oxide increases the risk of ethylene oxide accumulation; insufficient addition results in a low yield of tris(2-hydroxyethyl)methylammonium hydroxide, leading to a product with low basicity unsuitable for subsequent applications.

[0011] When using methylamine, methylethanolamine, or methyldiethanolamine as a raw material, the molar ratio of methylamine to ethylene oxide is 1:2.8-3.2; the molar ratio of methylethanolamine to ethylene oxide is 1:1.8-2.2; and the molar ratio of methyldiethanolamine to ethylene oxide is 1:0.8-1.2. The main objective of this invention is not to increase the yield of tris(2-hydroxyethyl)methylammonium hydroxide, the main component in quaternary ammonium alkali solution, but rather to facilitate subsequent applications. When the ratio of amine to ethylene oxide is as described above, a suitable yield can be obtained, and the risk of ethylene oxide accumulation is further reduced. More preferably, for example, the molar ratio of methylamine to ethylene oxide is 1:2.9; the molar ratio of methylethanolamine to ethylene oxide is 1:1.9; and the molar ratio of methyldiethanolamine to ethylene oxide is 1:0.9.

[0012] The reaction temperature is 30-70℃, and more preferably 40-60℃. A preferred temperature control method is to introduce ethylene oxide at room temperature, causing the material temperature to rise without additional heating, thus controlling the reaction system temperature at 40-60℃. When the reaction temperature does not exceed 60℃, the product is essentially colorless; above 60℃, it will appear pale yellow; and if the temperature is too high, it will become yellow or even brownish-yellow. When the reaction temperature is below 40℃, temperature control becomes difficult, energy consumption is high, and the reaction is slow, leading to ethylene oxide accumulation and a longer reaction time. More preferably, the reaction system temperature is controlled at 60℃.

[0013] Specifically, the following steps are included:

[0014] Step I: Add one or more of methylamine, methylethanolamine, and methyldiethanolamine, along with water, to a high-pressure reactor equipped with a stirrer and thermocouple. Turn on the stirrer, evacuate the reactor, connect a nitrogen cylinder to replace the air inside the reactor with nitrogen, and seal the reactor.

[0015] Step II: Slowly add ethylene oxide at room temperature. The reaction is exothermic, and the material temperature gradually rises. Control the reaction system temperature to 40-60℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate. Control the ethylene oxide addition rate to avoid material temperature fluctuations in the reactor exceeding 5℃, and control the reactor pressure to not exceed 0.5MPa.

[0016] Step III: After the ethylene oxide is fed in, continue the reaction for 0.5-10 hours with stirring;

[0017] Step IV: Stop the heat preservation, stir and bubble with nitrogen for 0.1-40 hours, then discharge the material to obtain a quaternary ammonium alkaline solution containing tris(2-hydroxyethyl)methylammonium hydroxide.

[0018] Room temperature typically refers to around 25 degrees Celsius. Slowly adding ethylene oxide at room temperature allows for gradual heating to the appropriate reaction temperature by utilizing the exothermic reaction itself. Compared to directly heating to 40-60 degrees Celsius, this saves energy and prevents problems such as the product turning pale yellow when directly heated to 40-60 degrees Celsius.

[0019] Additives are added during feeding or after discharging, and stirred evenly. The additives are selected from one or more of phenothiazine, hydroquinone, 4-methoxyphenol, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-p-methylphenol, ethylenediamine, hydroxyethylethylenediamine, and diethylhydroxylamine. The additives can delay the oxidative discoloration of the product.

[0020] The present invention also provides a cleaning solution composition after CMP in IC copper manufacturing process, wherein the mass percentage of each component is as follows: surfactant 0.01% to 1%, wetting agent 0.01% to 0.5%, organophosphorus chelating agent 0.01% to 2%, organoamine chelating agent 0.1% to 5%, quaternary ammonium alkali solution 5% to 10%, organic solvent 1% to 15%, defoamer 0.01% to 0.1%, pH adjuster 0.5% to 1.0%, and the balance being water, calculated by mass percentage; wherein the quaternary ammonium alkali solution is a product directly obtained by the preparation method of quaternary ammonium alkali solution in any of the above embodiments.

[0021] The composition provided by this invention is a water-based system composed of one or more organic amines and various complexing agents, suitable for post-CMP cleaning in semiconductor copper processes. As a cleaning solution, this composition effectively removes particles and organic residues from the wafer surface, ensuring high yield and reliability after CMP. To improve the surface quality of wafers after Cu-CMP cleaning, this invention provides a new proprietary alkaline cleaning agent with high cleaning efficiency, good cleaning effect, and good surface morphology profile, while also being environmentally friendly. Organophosphorus chelating agents can chelate insoluble copper ions and contaminant particles into water-soluble components, which are then removed by the cleaning solution. Wetting agents can penetrate into fine structures and remove contaminant particles through encapsulation. Organic amine chelating agents further enhance the complexing and encapsulation effect, improving cleaning efficiency. The quaternary ammonium alkaline solution provided in this invention improves cleaning efficiency. The concentration ratio of tris(2-hydroxyethyl)methylammonium hydroxide in the final product prepared using the above-mentioned quaternary ammonium alkaline solution preparation method is particularly suitable for direct use in preparing cleaning solutions.

[0022] The composition provided by this invention can be used as a cleaning solution to solve the surface finish problems of IC copper interconnect CMP, including pitting, organic residue, and micro-scratches. This invention uses a proprietary cleaning component containing a combination of penetrants, organophosphorus chelating agents, and organoamine chelating agents, which can effectively remove pitting and organic residues occurring during wafer CMP without scratching. The composition provided by this invention, as a cleaning solution, has high cleaning efficiency, short cleaning time, and good surface finish. The composition provided by this invention has a wide range of applications, suitable for post-IC-CMP cleaning and also for cleaning copper wafers; the composition provided by this invention, as a cleaning solution, is suitable for cleaning various integrated circuit wafers. The composition provided by this invention, as a cleaning solution, does not contain tetramethylammonium hydroxide (TMAH), is a green and environmentally friendly cleaning agent, is safe and reliable to use, and is low in cost.

[0023] The surfactant is selected from one or more of polyvinylpyrrolidone and fatty alcohol polyoxyethylene ether.

[0024] The wetting agent is acetylenic diol polyether; more specifically, 2,4,7,9-tetramethyl-5-decyn-4,7-diol polyoxyethylene ether, 2,5,8,11-tetramethyl-6-dodecyn-5,8-diol polyoxyethylene ether, etc., may be selected.

[0025] The organophosphorus chelating agent is selected from one or more of the following: 2-phosphonobutane-1,2,4-tricarboxylic acid, aminotrimethylphosphonic acid, ethylenediaminetetramethylphosphonic acid, diethylenetriaminepentamethylphosphonic acid, polyaminopolyethermethylenephosphonic acid, and hydroxyethylidene diphosphonic acid.

[0026] The organic amine chelating agent is selected from diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and their derivatives.

[0027] The organic solvent is selected from one or more of propylene glycol methyl ether, propylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, and diethylene glycol butyl ether.

[0028] The defoamer is a modified polysiloxane defoamer. The modified polysiloxane includes one or more of the following: polyether-modified polysiloxane, amino acid-modified polysiloxane, epoxy-modified polysiloxane, polyoxyalkylene-modified polysiloxane, polyglycerol-modified polysiloxane, glycerol-modified polysiloxane, and sugar-modified polysiloxane.

[0029] The pH adjuster is selected from ethanolamine, diethanolamine, triethanolamine, and their substituted derivatives.

[0030] This invention also provides products directly obtained by the preparation method of quaternary ammonium alkaline solution in any of the above-described embodiments, or the application of the compositions in any of the above-described embodiments in semiconductor manufacturing processes. Specifically, this could be its application in the preparation of cleaning solutions after CMP in IC copper processes, etc.

[0031] Compared with existing technologies, the present invention has at least the following beneficial effects: It provides a method for preparing a cleaning solution composition after CMP in IC copper processing, wherein the cleaning solution includes a quaternary ammonium alkali solution with tris(2-hydroxyethyl)methylammonium hydroxide as the main component; it utilizes the exothermic nature of the reaction, making temperature control easier, operation more convenient, and energy consumption lower; simultaneously, without using catalysts such as silica, the product contains fewer byproducts such as ethylene glycol. Furthermore, it reduces the risk of ethylene oxide accumulation, thus minimizing safety risks. More importantly, the main objective of the present invention is not to increase the yield of the main component tris(2-hydroxyethyl)methylammonium hydroxide in the quaternary ammonium alkali solution, but rather to facilitate subsequent applications; the components and content ratios in the quaternary ammonium alkali solution directly obtained by the preparation method of the present invention directly conform to the generally accepted specifications for alkaline substances in cleaning solutions. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart illustrating the specific steps in the preparation method of quaternary ammonium alkali solution in this embodiment of the invention.

[0034] Figure 2 This is a diagram showing the presence of dots in the copper wire area before cleaning;

[0035] Figure 3This is a diagram showing the presence of organic residue in the copper wire area before cleaning;

[0036] Figure 4 This is a diagram showing edge corrosion in the copper wire area before cleaning;

[0037] Figure 5 This is a diagram showing the presence of corrosion in the copper wire area before cleaning;

[0038] Figure 6 This is a diagram showing surface scratches in the copper wire area before cleaning;

[0039] Figure 7 This is a diagram showing micro-scratches in the copper wire area before cleaning;

[0040] Figure 8 This is a diagram showing the effect of cleaning the area behind the screen;

[0041] Figure 9 This is a diagram showing the effect of cleaning the wide-line area;

[0042] Figure 10 This is a diagram showing the effect of cleaning the fine line area;

[0043] Figure 11 This is a diagram showing the effect of cleaning the interconnects and TEOS (tetraethyl orthosilicate) surface;

[0044] Figure 12 This is a diagram showing the effect of cleaning the copper wire array area;

[0045] Figure 13 This is a diagram showing the effect of cleaning the wide line array area. Detailed Implementation

[0046] The technical solutions in specific embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The specific steps in the preparation methods of some of the following embodiments are as follows: Figure 1 The flowchart (and some of the preparation methods in the embodiments are similar) Figure 1 The steps shown are slightly different; the flowchart is for reference only.

[0047] 1. A method for preparing a quaternary ammonium alkaline solution containing tris(2-hydroxyethyl)methylammonium hydroxide (THEMAH) is provided. (1) Methylamine is added according to the following Examples 1-5 and Comparative Examples 1-4:

[0048] Comparative Example 1

[0049] The 2L stainless steel autoclave equipped with a stirrer and thermocouple was pre-rinsed with pure water. 347g of a 40% methylamine aqueous solution was added (the methylamine aqueous solution was obtained by passing methylamine gas into water beforehand, as in Examples 1-5 and Comparative Examples 1-4 below), and 330g of pure water (4.6 eq). The stirrer was turned on, and a vacuum was created using a water pump while stirring. The air inside the autoclave was replaced three times with N2 from a gas cylinder, and the autoclave was then sealed.

[0050] A circulating cooling system was started, and the temperature was controlled at 20°C. Ethylene oxide gas was slowly introduced, and the reaction system temperature was controlled at 20±5°C during the ethylene oxide introduction. After adding 400g of ethylene oxide (2 eq), the ethylene oxide introduction was stopped, and the mixture was stirred at 20°C for 0.5 hours. Then, the material was bubbled with nitrogen under low-speed stirring for 0.1 hours. After discharging, 10ppm of 4-methoxyphenol (MEHQ) was added, and the mixture was stirred evenly. The resulting product was a colorless liquid with a pH of 11.83 after 100-fold dilution. The 1H NMR spectrum showed that the product mainly consisted of methyldiethanolamine (MDEA), with small amounts of methylethanolamine and tris(2-hydroxyethyl)methylammonium hydroxide (THEMAH). The conversion rates of methylamine to MDEA and THEMAH were 85.5% and 6.3%, respectively. Based on the conversion rates and feed amounts, the product contained 2.6% methylethanolamine, 43.0% MDEA, and 4.8% THEMAH.

[0051] Comparative Example 2

[0052] The method for preparing a quaternary ammonium alkali solution containing THEMAH was followed by addition of 600 g of ethylene oxide (3 eq), stirring at 20°C for 10 hours, followed by nitrogen bubbling and rinsing under low-speed stirring for 2 hours, and then discharging. After discharging, 500 ppm MEHQ was added and stirred until homogeneous. The resulting product was a colorless liquid with a pH of 12.25 after 100-fold dilution. 1H NMR spectroscopy showed that all methylamine was converted to MDEA and THEMAH, with a conversion rate of 65.8% for methylamine to THEMAH. Based on the conversion rate and feed amount, the product contained 42.4% THEMAH and 17.2% MDEA.

[0053] Comparative Example 3

[0054] The method for preparing a quaternary ammonium alkaline solution containing THEMAH was followed according to Comparative Example 1, except that 1000 g of ethylene oxide (5.1 eq) was added, the mixture was stirred at 20°C for 2 hours, and then purged with nitrogen under low-speed stirring for 10 hours before being discharged. After discharge, 500 ppm of hydroquinone was added and stirred until homogeneous. The resulting product was a colorless liquid with a pH of 12.75 after 100-fold dilution. 1H NMR spectroscopy showed that all methylamine was converted to MDEA and THEMAH, with a conversion rate of 95.4% for methylamine to THEMAH. Based on the conversion rate and feed amount, the product contained 46.8% THEMAH and 1.5% MDEA.

[0055] Comparative Example 4

[0056] The method for preparing a quaternary ammonium alkali solution containing THEMAH was followed according to Comparative Example 1, except that 53 g of water (0.65 eq) and 600 g of ethylene oxide (3 eq) were added. After heating to 70 °C, ethylene oxide was introduced. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 100 ± 5 °C, and the pressure inside the reactor was controlled not to exceed 0.5 MPa. After the ethylene oxide was completely introduced, the mixture was stirred at 100 °C for 0.5 hours without nitrogen rinsing. After discharge, 1000 ppm ethylenediamine was added and stirred until homogeneous. The resulting product was a brownish-yellow viscous liquid. After dilution 100 times, the pH was 12.67. 1H NMR spectroscopy showed that all methylamine was converted to MDEA and THEMAH, with a conversion rate of 68.3%. Based on the conversion rate and the amount of feed, the product contained 56.2% THEMAH and 17.2% MDEA.

[0057] Example 1

[0058] A 2L stainless steel autoclave equipped with a stirrer and thermocouple was pre-rinsed with pure water. 347g of a 40% methylamine aqueous solution and 330g of pure water (4.6 eq) were added. Stirring was started, and a vacuum was created using a water pump while stirring. The air inside the autoclave was replaced three times with N2 from a gas cylinder, and the autoclave was then sealed. 580g of ethylene oxide (2.9 eq) was added, and ethylene oxide was slowly introduced at room temperature. The reaction was exothermic, and the material temperature gradually increased. Without additional heating, the reaction system temperature was controlled at 60±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate. The pressure inside the autoclave was controlled not to exceed 0.5MPa. After the ethylene oxide was completely introduced, the autoclave was stirred at 60℃ for 4 hours. The temperature was then stopped, and the autoclave was rinsed with nitrogen bubbling under low-speed stirring for 3 hours before discharging. After discharging, 1000ppm of 2,5-di-tert-butylhydroquinone (BHQ) was added and stirred until homogeneous. The resulting product was a colorless liquid with a pH of 12.42 after 100-fold dilution. A 1H NMR spectrum showed that all methylamine was converted to MDEA and THEMAH, with a conversion rate of 72.6% for methylamine to THEMAH. Based on the conversion rate and feed amount, the product contained 46.8% THEMAH and 11.6% MDEA.

[0059] Example 2

[0060] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 1 differs in that 308g of a 40% methylamine aqueous solution, 235g of pure water (3.24eq), and 568g of ethylene oxide (3.2eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 6 hours, then the temperature is stopped, and the mixture is rinsed with nitrogen under low-speed stirring for 3 hours before being discharged. After discharge, 3000ppm of hydroxyethyl ethylenediamine is added and stirred until homogeneous. The resulting product is a colorless liquid with a pH of 12.59 after 100-fold dilution. A 1H NMR spectroscopy analysis shows that all methylamine is converted to MDEA and THEMAH, with a conversion rate of 85.1% for methylamine to THEMAH. Based on conversion rate and feed amount, the product contains 56.0% THEMAH and 6.4% MDEA.

[0061] Example 3

[0062] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 1 differs in that 298g of a 40% methylamine aqueous solution, 190g of pure water (2.69eq), and 529g of ethylene oxide (3.08eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 60±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 60℃ for 8 hours. The temperature is then stopped, and the mixture is rinsed with nitrogen under low-speed stirring for 5 hours before being discharged. After discharge, 5000ppm of diethylhydroxylamine is added, and the mixture is stirred until homogeneous. The resulting product is a light yellow liquid. After dilution 100 times, the pH is 12.51. A 1H NMR spectroscopy shows that all methylamine is converted to MDEA and THEMAH, with a conversion rate of 74.3% for methylamine to THEMAH. Based on conversion rate and feed amount, the product contains 51.7% THEMAH and 11.8% MDEA.

[0063] Example 4

[0064] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 1 differs in that water is not added, but 640g of ethylene oxide (3.2eq) is added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, causing the material temperature to gradually rise. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 2 hours, then the temperature is stopped, and the mixture is rinsed with nitrogen under low-speed stirring for 3 hours before being discharged. After discharge, 20000ppm of hydroxyethyl ethylenediamine is added and stirred until homogeneous. The resulting product is a colorless viscous liquid. After dilution 100 times, the pH is 12.61. A 1H NMR spectrum shows that all methylamine is converted to MDEA and THEMAH, with a conversion rate of 48.3% for methylamine to THEMAH. Based on the conversion rate and the amount of material added, the product contains 40.3% THEMAH and 28.4% MDEA.

[0065] Example 5

[0066] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 1 differs in that water is not added; instead, 640 g of ethylene oxide (3.2 eq) and 2.96 g of hydroxyethyl ethylenediamine (3000 ppm) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50 ± 5 °C by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5 MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50 °C for 2 hours, then the temperature is stopped, and the mixture is rinsed with nitrogen under low-speed stirring for 3 hours before being discharged. The resulting product is a colorless viscous liquid. After diluting 100 times, the pH is 12.59. A 1H NMR spectrum shows that all methylamine is converted to MDEA and THEMAH, with a conversion rate of 45.7% for methylamine to THEMAH. Based on the conversion rate and the amount of feed, the product contains 38.0% THEMAH and 29.7% MDEA.

[0067] (2) The addition of methylethanolamine (MMEA) is as described in Examples 6-8 and Comparative Examples 5-10 below:

[0068] Comparative Example 5

[0069] The 2L stainless steel autoclave equipped with a stirrer and thermocouple was pre-rinsed with pure water. 383g of methylethanolamine, 208g of pure water (2.3eq), and 1.02g of MEHQ (1255ppm) were added. The stirrer was turned on, and a vacuum was drawn using a water pump while stirring. The air inside the autoclave was replaced three times with N2 from an N2 cylinder, and then the autoclave was sealed.

[0070] A circulating cooling system was started, and the temperature was controlled at 20°C. Ethylene oxide gas was slowly introduced, and the reaction system temperature was controlled at 20±5°C during the ethylene oxide introduction. After adding 222g of ethylene oxide (1 eq), the ethylene oxide introduction was stopped, and the mixture was stirred at 20°C for 2 hours. Then, the mixture was bubbled with nitrogen under low-speed stirring for 0.1 hours, and a colorless liquid was discharged. The pH of the obtained product after diluting 100 times was 11.81. The 1H NMR spectrum showed that the product mainly consisted of methyldiethanolamine (MDEA), with small amounts of methylethanolamine and tris(2-hydroxyethyl)methylammonium hydroxide (THEMAH). The conversion rates of methylethanolamine to MDEA and THEMAH were 84.7% and 6.9%, respectively. Based on the conversion rates and feed amounts, the product contained 3.9% methylethanolamine, 62.7% MDEA, and 7.8% THEMAH.

[0071] Comparative Example 6

[0072] The 2L stainless steel autoclave equipped with a stirrer and thermocouple was pre-rinsed with pure water. 383g of methylethanolamine and 208g of pure water (2.3eq) were added. The stirrer was turned on, and a vacuum was drawn using a water pump while stirring. The air inside the autoclave was replaced three times with N2 from an N2 cylinder, and then the autoclave was sealed.

[0073] A circulating cooling system was started, and the temperature was controlled at 20°C. Ethylene oxide gas was slowly introduced, and the reaction system temperature was controlled at 20±5°C during the ethylene oxide introduction. After adding 1112g of ethylene oxide (4.9eq), the ethylene oxide introduction was stopped, and the mixture was stirred at 20°C for 10 hours. Then, the material was bubbled and washed with nitrogen under low-speed stirring for 40 hours, and a colorless liquid was discharged. After discharge, 10ppm of hydroxyethyl ethylenediamine was added, and the mixture was stirred evenly. The pH of the product after being diluted 100 times was 12.57. The 1H NMR spectrum showed that methylethanolamine was completely converted to MDEA and THEMAH, with a conversion rate of 99.5% for methylethanolamine to THEMAH. Based on the conversion rate and the amount of feed, the product contained 53.5% THEMAH and 0.2% MDEA.

[0074] Comparative Example 7

[0075] The method for preparing a quaternary ammonium alkali solution containing THEMAH was based on Comparative Example 6, except that 910 g of water (10 eq) and 667 g of ethylene oxide (3 eq) were added. After heating to 70°C, ethylene oxide was introduced. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 100 ± 5°C, and the pressure inside the reactor was controlled not to exceed 0.5 MPa. After the ethylene oxide was completely introduced, the mixture was stirred at 100°C for 0.5 hours. The heat was then stopped, and the mixture was bubbled with nitrogen under low-speed stirring for 5 hours, yielding a yellow liquid. After discharging, 500 ppm MEHQ was added, and the mixture was stirred evenly. After diluting 100 times, the pH was 12.35. A 1H NMR spectroscopy showed that methylethanolamine was completely converted to MDEA and THEMAH, with a conversion rate of 92.5% for methylethanolamine to THEMAH. Based on the conversion rate and the amount of feed, the product contained 43.2% THEMAH and 2.3% MDEA.

[0076] Comparative Example 8

[0077] The method for preparing a quaternary ammonium alkali solution containing THEMAH was based on Comparative Example 6, except that 208 g of water (2.3 eq) and 445 g of ethylene oxide (2 eq) were added. After heating to 40°C, ethylene oxide was introduced. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 90 ± 5°C, and the pressure inside the reactor was controlled not to exceed 0.5 MPa. After the ethylene oxide was completely introduced, the mixture was stirred at 90°C for 0.7 hours. The heat was then stopped, and the mixture was bubbled with nitrogen at low speed for 2 hours. A brownish-yellow liquid was discharged. After discharge, 1000 ppm MEHQ was added, stirred evenly, and diluted 100 times. The pH was 12.25. A 1H NMR spectroscopy showed that methylethanolamine was completely converted to MDEA and THEMAH, with a conversion rate of 43.4% for methylethanolamine to THEMAH. Based on the conversion rate and the amount of feed, the product contained 38.3% THEMAH and 32.9% MDEA.

[0078] Comparative Example 9

[0079] The method for preparing a quaternary ammonium alkali solution containing THEMAH was based on Comparative Example 6, except that 299g of methylethanolamine, 367g of water (3.7 eq), and 347g of ethylene oxide (2 eq) were added. The mixture was heated to 50℃, and ethylene oxide was introduced. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 90±5℃, and the pressure inside the reactor was controlled not to exceed 0.5MPa. After the ethylene oxide was completely introduced, the mixture was stirred at 90℃ for 1 hour. No nitrogen rinsing was required, and a yellow liquid was discharged. After discharge, 1000ppm of 2,5-di-tert-butylhydroquinone (BHQ) was added, stirred evenly, and diluted 100 times to a pH of 12.33. A 1H NMR spectroscopy showed that all methylethanolamine was converted to MDEA and THEMAH, with a conversion rate of 66.9%. Based on the conversion rate and the amount of feed, the product contained 47.2% THEMAH and 15.3% MDEA.

[0080] Comparative Example 10

[0081] The method for preparing a quaternary ammonium alkali solution containing THEMAH was based on Comparative Example 6, except that 295g of methylethanolamine, 425g of water (6.1 eq), and 304g of ethylene oxide (1.8 eq) were added. The mixture was heated to 40℃, and ethylene oxide was introduced. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 50±5℃, and the pressure inside the reactor was controlled not to exceed 0.5MPa. After the ethylene oxide was completely introduced, the mixture was stirred at 50℃ for 0.5 hours. The heat was then stopped, and the mixture was bubbled with nitrogen under low-speed stirring for 3 hours, yielding a light yellow liquid. After discharging, 5000ppm of diethylhydroxylamine was added, and the mixture was stirred evenly. After dilution 100 times, the pH was 12.38. A 1H NMR spectroscopy showed that all methylethanolamine was converted to MDEA and THEMAH, with a conversion rate of 60.9%. Based on the conversion rate and the amount of feed, the product contained 41.9% THEMAH and 17.7% MDEA.

[0082] Example 6

[0083] A 2L stainless steel autoclave equipped with a stirrer and thermocouple was pre-rinsed with pure water. 299g of methylethanolamine and 473g of water (6.7 eq) were added, and stirring was started. A vacuum was created using a water pump while stirring, and the air inside the autoclave was replaced three times with N2 from a gas cylinder. The autoclave was then sealed. 330g of ethylene oxide (1.9 eq) was added, and ethylene oxide was slowly introduced at room temperature. The reaction was exothermic, and the material temperature gradually increased. Without additional heating, the reaction system temperature was controlled at 60±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the autoclave was controlled not to exceed 0.5MPa. After the ethylene oxide was completely introduced, the autoclave was stirred at 60℃ for 4 hours. The temperature was then stopped, and the autoclave was rinsed with nitrogen bubbling under low-speed stirring for 3.5 hours. A colorless liquid was then discharged. After discharge, 1000 ppm MEHQ was added and stirred evenly. After dilution 100 times, the pH was 12.42. The 1H NMR spectrum showed that methylethanolamine was completely converted into MDEA and THEMAH, with a conversion rate of 71.4% for methylethanolamine to THEMAH. Based on the conversion rate and feed amount, the product contained 46.2% THEMAH and 12.2% MDEA.

[0084] Example 7

[0085] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 6 differs in that 385g of methylethanolamine, 150g of water (1.6 eq), and 467g of ethylene oxide (2.1 eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. Without additional heating, the reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 2 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen under low-speed stirring for 2 hours. A colorless, viscous liquid is discharged. After discharge, 2500ppm of hydroxyethyl ethylenediamine is added, stirred evenly, and diluted 100 times. The pH is 12.63. A 1H NMR spectrum shows that all methylethanolamine is converted to MDEA and THEMAH, with a conversion rate of 33.5% for methylethanolamine to THEMAH. Based on conversion rate and feed amount, the product contains 30.8% THEMAH and 40.2% MDEA.

[0086] Example 8

[0087] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 6 differs in that 270g of methylethanolamine, 429g of water (6.7eq), and 378g of ethylene oxide (2.4eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. Without additional heating, the reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 24 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen at low speed for 2 hours. A light yellow liquid is discharged. After discharge, 3500ppm of diethylhydroxylamine is added, stirred evenly, and diluted 100 times. The pH is 12.69. A 1H NMR spectrum shows that all methylethanolamine is converted to MDEA and THEMAH, with a conversion rate of 73.9% for methylethanolamine to THEMAH. Based on conversion rate and feed amount, the product contains 44.4% THEMAH and 10.3% MDEA.

[0088] (3) The addition of methyldiethanolamine (MDEA) is as described in Examples 9-16 and Comparative Examples 11-14 below:

[0089] Comparative Example 11

[0090] The 2L stainless steel autoclave equipped with a stirrer and thermocouple was pre-rinsed with pure water. 468g MDEA, 426g pure water (6.1 eq), and 0.55g MEHQ (500ppm) were added. Stirring was started, and a vacuum was created using a water pump while stirring. The air inside the autoclave was replaced three times with N2 from a gas cylinder. The autoclave was then sealed.

[0091] A circulating cooling system was started, and the temperature was controlled at 20°C. Ethylene oxide gas was slowly introduced, and the reaction system temperature was controlled at 20±5°C during the ethylene oxide introduction. After adding 171g of ethylene oxide (1 eq), the ethylene oxide introduction was stopped, and the mixture was stirred at 20°C for 0.5 hours. Then, the material was bubbled with nitrogen under low-speed stirring for 0.1 hours, and a colorless liquid was discharged. The pH of the obtained product after 100-fold dilution was 12.22, and the 1H NMR spectrum showed that the conversion rate of MDEA to THEMAH was 59.4%. Based on the conversion rate and the amount of feed, the product contained 39.2% THEMAH and 17.6% MDEA.

[0092] Comparative Example 12

[0093] The method for preparing a quaternary ammonium alkali solution containing THEMAH was similar to Comparative Example 11, except that ethylene oxide was introduced after heating to 40°C. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 90±5°C, and the pressure inside the reactor was controlled not to exceed 0.5 MPa. After the ethylene oxide introduction was complete, the mixture was stirred at 90°C for 0.5 hours. Nitrogen rinsing was not used, and a yellow liquid was discharged. The pH of the obtained product after 100-fold dilution was 12.33. A 1H NMR spectroscopy showed that the conversion rate of MDEA to THEMAH was 65.0%. Based on the conversion rate and the amount of material fed, the product contained 43.0% THEMAH and 15.2% MDEA.

[0094] Comparative Example 13

[0095] Rinse the 2L stainless steel autoclave equipped with a stirrer and thermocouple with pure water beforehand, then add 470g MDEA and 427g pure water (6.1eq). Turn on the stirrer, and use a water pump to create a vacuum while stirring. Connect an N2 cylinder and replace the air in the autoclave with N2 three times, then seal the autoclave.

[0096] After heating to 50℃, ethylene oxide was introduced. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 100±5℃, and the pressure inside the reactor was controlled not to exceed 0.5MPa. After adding 172g of ethylene oxide (1eq), the mixture was stirred at 100℃ for 0.5 hours. Heating was stopped, and the material was bubbled with nitrogen under low-speed stirring for 1 hour, yielding a yellow liquid. After discharging, 1000ppm of 2,5-di-tert-butylhydroquinone (BHQ) was added and stirred until homogeneous. After dilution 100 times, the pH was 12.29. A 1H NMR spectroscopy study showed that the conversion rate of MDEA to THEMAH was 55.6%. Based on the conversion rate and the amount of material fed, the product contained 36.8% THEMAH and 19.3% MDEA.

[0097] Comparative Example 14

[0098] The method for preparing a quaternary ammonium alkali solution containing THEMAH was similar to Comparative Example 13, except that ethylene oxide was introduced after heating to 40°C. The reaction was exothermic, and the material temperature gradually increased. During the introduction of ethylene oxide, the reaction system temperature was controlled at 65±5°C, and the pressure inside the reactor was controlled not to exceed 0.5 MPa. After the ethylene oxide was completely introduced, the mixture was stirred at 65°C for 10 hours. The heat was then stopped, and the material was bubbled with nitrogen under low-speed stirring for 10 hours, yielding a light yellow liquid. After discharging, 2500 ppm of hydroxyethyl ethylenediamine was added, stirred evenly, and diluted 100 times. The pH was 12.35. A 1H NMR spectroscopy showed that the conversion rate of MDEA to THEMAH was 69.6%. Based on the conversion rate and the amount of material added, the product contained 46.1% THEMAH and 13.2% MDEA.

[0099] Example 9

[0100] A 2L stainless steel autoclave equipped with a stirrer and thermocouple was pre-rinsed with pure water. 660g MDEA, 602g water (6.1 eq), and 181g ethylene oxide (0.7 eq) were added. Ethylene oxide was slowly introduced at room temperature, and the reaction was exothermic, causing the material temperature to gradually rise. Without additional heating, the reaction system temperature was controlled at 55±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the autoclave was controlled not to exceed 0.5MPa. After the ethylene oxide was completely introduced, the autoclave was stirred at 55℃ for 1 hour. The temperature was then stopped, and the material was bubbled with nitrogen under low-speed stirring for 3 hours. A colorless liquid was discharged. After discharge, 3500ppm diethylhydroxylamine was added and stirred until homogeneous. After dilution 100 times, the pH was 12.41. A 1H NMR spectroscopy study showed that the conversion rate of MDEA to THEMAH was 61.7%. Based on the conversion rate and the amount of material added, the product contained 42.6% THEMAH and 17.4% MDEA.

[0101] Example 10

[0102] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 9 differs in that 472g MDEA, 472g water (6.7eq), and 163g ethylene oxide (0.9eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 2 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen under low-speed stirring for 3 hours. A colorless liquid is discharged. After discharge, 3500ppm diethylhydroxylamine is added, stirred evenly, and diluted 100 times. The pH is 12.39. A 1H NMR spectrum shows that the conversion rate of MDEA to THEMAH is 66.9%. Based on the conversion rate and the amount of feed, the product contains 42.9% THEMAH and 14.0% MDEA.

[0103] Example 11

[0104] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 9 differs in that 472g MDEA, 472g water (6.7 eq), and 346g ethylene oxide (2 eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 4 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen under low-speed stirring for 5 hours. A colorless liquid is discharged. After discharge, 2500ppm hydroxyethyl ethylenediamine is added, stirred evenly, and diluted 100 times to a pH of 12.53. A 1H NMR spectroscopy shows that the conversion rate of MDEA to THEMAH is 98.4%. Based on the conversion rate and the amount of feed, the product contains 54.2% THEMAH and 0.6% MDEA.

[0105] Example 12

[0106] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 9 differs in that 660g MDEA, 602g water (6.1 eq), and 218g ethylene oxide (0.9 eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. Without additional heating, the reaction system temperature is controlled at 60±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 60℃ for 4 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen at low speed for 3 hours. A colorless liquid is discharged. After discharge, 3500ppm diethylhydroxylamine is added, stirred evenly, and diluted 100 times to a pH of 12.45. A 1H NMR spectrum shows that the conversion rate of MDEA to THEMAH is 68.8%. Based on the conversion rate and the amount of feed, the product contains 46.4% THEMAH and 13.8% MDEA.

[0107] Example 13

[0108] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 9 differs in that 473g MDEA, 494g water (7.0 eq), and 190g ethylene oxide (1.1 eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 1 hour, then the temperature is stopped, and the mixture is bubbled with nitrogen at low speed for 2.5 hours. A colorless liquid is discharged. After discharge, 500ppm MEHQ is added, stirred evenly, and diluted 100 times. The pH is 12.38. A 1H NMR spectrum shows that the conversion rate of MDEA to THEMAH is 76.8%. Based on the conversion rate and the amount of feed, the product contains 47.3% THEMAH and 9.4% MDEA.

[0109] Example 14

[0110] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 9 differs in that 471g MDEA, 470g water (6.7eq), and 185g ethylene oxide (1.08eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 2 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen at low speed for 4 hours. A colorless liquid is discharged. After discharge, 1000ppm MEHQ is added, stirred evenly, and diluted 100 times. The pH is 12.39. A 1H NMR spectrum shows that the conversion rate of MDEA to THEMAH is 73.6%. Based on the conversion rate and the amount of feed, the product contains 46.2% THEMAH and 10.9% MDEA.

[0111] Example 15

[0112] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 9 differs in that 470g MDEA, 367g water (5.2eq), and 184g ethylene oxide (1.07eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 2 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen under low-speed stirring for 3 hours. A colorless liquid is discharged. After discharge, 1000ppm MEHQ is added, stirred evenly, and diluted 100 times, resulting in a pH of 12.39. A 1H NMR spectrum shows that the conversion rate of MDEA to THEMAH is 74.9%. Based on the conversion rate and the amount of feed, the product contains 51.9% THEMAH and 11.4% MDEA.

[0113] Example 16

[0114] The method for preparing a quaternary ammonium alkali solution containing THEMAH according to Example 9 differs in that 471g MDEA, 164g water (2.3eq), and 185g ethylene oxide (1.07eq) are added. Ethylene oxide is slowly introduced at room temperature, and the reaction is exothermic, with the material temperature gradually rising. No additional heating is required. The reaction system temperature is controlled at 50±5℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate, and the pressure inside the reactor is controlled not to exceed 0.5MPa. After the ethylene oxide is completely introduced, the mixture is stirred at 50℃ for 2 hours, then the temperature is stopped, and the mixture is bubbled with nitrogen at low speed for 3 hours. A colorless, viscous liquid is discharged. After discharge, 20000ppm hydroxyethyl ethylenediamine is added and stirred evenly. The resulting product, diluted 100 times, has a pH of 12.61. A 1H NMR spectrum shows that the conversion rate of MDEA to THEMAH is 47.6%. Based on the conversion rate and the amount of feed, the product contains 41.3% THEMAH and 29.9% MDEA.

[0115] Comparative Example 15

[0116] 357 g of methyldiethanolamine and 489 g of deionized water were introduced into a 2-liter three-necked flask equipped with a thermometer, stirrer, dry ice condenser, cooling bath, and nitrogen inlet. The mixture was stirred, and approximately 115 g of ethylene oxide was fed into the reaction mixture through a feed tube, maintaining the reaction temperature below 20°C. After the ethylene oxide was added dropwise, the reaction mixture was digested for one hour. The reaction mixture was then purged with nitrogen for one hour; the product was a clear, colorless liquid. An aqueous solution of tris(2-hydroxyethyl)methylammonium hydroxide (THEMAH) was prepared using methyldiethanolamine and ethylene oxide at temperatures below 20°C.

[0117] Comparative Example 16

[0118] The difference from Example 1 is that 45g of silica sol (29-31% silica content) was added as a catalyst and 299g of water was added during feeding. The resulting product was a colorless liquid with a pH of 12.49 after 100-fold dilution. 1H NMR spectroscopy showed that all methylamine was converted to MDEA and THEMAH, with a conversion rate of 74.1% for methylamine to THEMAH. Based on the conversion rate and the amount of feed, the product contained 47.2% THEMAH and 10.9% MDEA.

[0119] Example 17

[0120] The difference from Example 1 is that 1160g of ethylene oxide (5.8 eq) was added, resulting in a colorless liquid. After dilution 100 times, the pH was 12.77. A 1H NMR spectrum showed that all methylamine was converted to MDEA and THEMAH, with a conversion rate of 97.5% for methylamine to THEMAH. Based on the conversion rate and feed amount, the product contained 43.0% THEMAH and 0.7% MDEA.

[0121] The test conditions and results for some of the embodiments and comparative examples are shown in Tables 1-3 below:

[0122] Table 1. Some experimental conditions and results of the reaction between methylamine and ethylene oxide.

[0123]

[0124] Where EO refers to ethylene oxide, amine refers to methyl ethanolamine (in Table 1), methyl ethanolamine (in Table 2), or methyl diethanolamine (in Table 3), and EO:amine is the molar ratio of EO to amine. Room temperature - 50 means that ethylene oxide is fed from room temperature, and the reaction temperature is ultimately controlled at 50 ± 5℃, and the same applies to other conditions. Temperature 70-100 means that ethylene oxide is first heated to 70℃ before feeding, and the reaction temperature is ultimately controlled at 100 ± 5℃, and the same applies to other conditions.

[0125] Table 2. Some experimental conditions and results of the reaction between methylethanolamine and ethylene oxide.

[0126]

[0127] Table 3. Some experimental conditions and results of the reaction between methyldiethanolamine and ethylene oxide.

[0128]

[0129]

[0130] The reaction temperature control method of Examples 1-17 above is to start the reaction at room temperature and control the temperature of the reaction system to a certain temperature after a period of time; the reaction temperature control method of Comparative Examples 1-15 above is to control the reaction to start at a specific temperature. Its temperature control is complicated and its energy consumption is higher than that of Examples 1-17. Therefore, it is used as a comparative example, but it still belongs to the technical solution of the present invention.

[0131] Commercially available quaternary ammonium alkali solutions containing THEMAH are generally aqueous solutions with a THEMAH content of 45-50%, containing a portion of MDEA and stabilizers. In semiconductor manufacturing processes, this concentration of THEMAH-containing quaternary ammonium alkali solution is generally used directly to prepare cleaning solutions and other compositions. Therefore, to facilitate application in subsequent semiconductor manufacturing processes such as the preparation of cleaning solutions after CMP in IC copper processes, the products prepared in Examples 1, 6, 12, 13, and 14 are selected as the more ideal final quaternary ammonium alkali solution compositions. The preferred principles for the examples are: the ideal product is colorless and non-viscous; a simple temperature control method starting at room temperature saves energy; and the THEMAH content is 45-50%. Furthermore, the commercially available THEMAH-containing quaternary ammonium alkali solutions contain 11.5-14% methyldiethanolamine. To ensure the subsequent use of the quaternary ammonium alkali solution composition, it is necessary to meet the specifications for the alkaline content in the cleaning solution. Therefore, the most preferred examples are Examples 1, 6, and 12. In the preferred embodiment, the reaction conditions are as follows: when using methylamine, methylethanolamine, or methyldiethanolamine as raw materials, the molar ratio of methylamine to ethylene oxide is 1:2.9; the molar ratio of methylethanolamine to ethylene oxide is 1:1.9; and the molar ratio of methyldiethanolamine to ethylene oxide is 1:0.9. The temperature control method is as follows: ethylene oxide is introduced at room temperature, the material temperature rises, no additional heating is required, the reaction system temperature is controlled at 60°C, and the reaction time is 4 hours. An appropriate amount of water is added to avoid product viscosity, resulting in a synergistic effect.

[0132] Taking cleaning fluid compositions as an example, a 45-50% THEMAH aqueous solution is commonly used as a strongly alkaline substance in alkaline cleaning fluids. One of the objectives of this invention is to provide a method for preparing quaternary ammonium alkaline solutions, so that the content of THEMAH in the prepared product can directly meet the generally accepted specifications for alkaline substances in cleaning fluids. Simultaneously, this preparation method can cleverly solve the problems of complex temperature control and easy accumulation of ethylene oxide in existing technologies. For example, in Comparative Example 15, the temperature needs to be controlled below 20°C, which is complex. The reaction is strongly exothermic, and cooling below 20°C requires the use of media such as dry ice, making operation inconvenient and unsuitable for scale-up production. In Example 17, the addition of excessive ethylene oxide leads to ethylene oxide accumulation, posing a significant safety risk; while the THEMAH conversion rate is improved, the methyldiethanolamine content is too low to meet the alkalinity requirements for subsequent cleaning fluid applications. In Comparative Example 16, silica sol (29-31% silica content) is added as a catalyst, increasing the reaction rate, but residual catalyst remains in the product, making it inconvenient for direct application in the preparation of subsequent cleaning fluids. This invention achieves simple temperature control that perfectly meets the needs of subsequent use by sacrificing a portion of the conversion rate.

[0133] The heating / temperature control methods mentioned in the comparative examples and embodiments above are of three types: first, controlling the temperature at a specific temperature to complete the entire reaction; second, raising the temperature to a certain level, reacting for a period of time, and then controlling the temperature to continue the reaction at a higher level; and third, starting the reaction at room temperature, reacting for a period of time, and then controlling the temperature to continue the reaction. Comparative Examples 1-3, 5-6, and 11 all controlled the temperature at 20°C for the reaction, resulting in high energy consumption.

[0134] Comparative Example 10 was initially heated to 40°C to initiate the reaction, and then maintained at 50°C for further reaction. Comparative Example 14 was initially heated to 40°C to initiate the reaction, and then maintained at 65°C for further reaction. Comparative Examples 8 and 12 were initially heated to 40°C to initiate the reaction, and then maintained at 90°C for further reaction. Comparative Example 9 was initially heated to 50°C to initiate the reaction, and then maintained at 90°C for further reaction. Comparative Example 13 was initially heated to 50°C to initiate the reaction, and then maintained at 100°C for further reaction. Comparative Examples 4 and 7 were initially heated to 70°C to initiate the reaction, and then maintained at 100°C for further reaction. Examples 1-16 were all heated from room temperature for a period of time, and then maintained at 50-60°C for further reaction. In Example 3, the product was heated at 60°C for 8 hours; prolonged heating caused the product to turn pale yellow. In Example 8, the product was heated at 50°C for 24 hours; prolonged heating caused the product to turn pale yellow.

[0135] It can be seen that products meeting the final requirements are generally obtained through a heating method that starts the reaction at room temperature for a period of time and continues the reaction at a controlled temperature. Specifically, when heated from room temperature to no more than 65°C for a short period, the product is essentially colorless. Heating above 65°C or above 50°C for an extended period will result in a light yellow color. If the temperature is too high, the product will turn yellow or even brownish-yellow. If the initial temperature is higher than room temperature, such as reaching 40°C, the product is also likely to turn light yellow. Non-colorless products are not suitable for subsequent use as standard cleaning solutions.

[0136] Secondly, the amount of water equivalence must be appropriate. If too little water is used, the viscosity of the system increases significantly in the later stages of the reaction, resulting in lower mixing efficiency between ethylene oxide gas and materials, thus affecting the conversion rate. For example, the products obtained in Comparative Example 4, Example 4, Example 5, Example 7, and Example 16 were all viscous liquids. The less water used, the more viscous the product. Viscous products are unsuitable for subsequent use as standard cleaning solutions.

[0137] The conversion rate of Example 9 was 61.7% (slightly low, possibly due to insufficient ethylene oxide addition), and the THEMAH content was low. Example 11 had a conversion rate of 98.4%. Although the conversion rate was high, the excessive ethylene oxide led to an increase in byproducts such as ethylene glycol, while the insufficient methyldiethanolamine content did not meet the requirements for alkaline substances in the subsequent cleaning solution. Comparative Example 16 had a slightly higher conversion rate than without catalyst, but catalyst residue remained in the product, making it unsuitable for direct application. Example 8 had a conversion rate of 73.9%, and the THEMAH content was also suitable, but excessive stirring time caused the product color to be slightly yellow. While excessive ethylene oxide increases the THEMAH yield, it also leads to ethylene oxide accumulation in the reactor, posing a significant safety risk; insufficient ethylene oxide results in a low yield and reduced production economics. Example 17 had a large excess of ethylene oxide, which significantly increased byproducts such as ethylene glycol in the product, leading to a decrease in THEMAH content.

[0138] Furthermore, different additives, namely antioxidants, can produce different antioxidant effects. Without antioxidants, the product is prone to discoloration and yellowing during storage. Adding antioxidants can extend the time the product remains colorfast during storage. Different antioxidants and their amounts will affect the duration of colorfastness during storage.

[0139] Therefore, to obtain the ideal quaternary ammonium alkali solution composition, the temperature control method involves starting the reaction at room temperature for a period of time, then continuing the reaction at 40-60°C for 2-4 hours. Heating at 60°C for less than 4 hours results in a colorless product. A more preferred reaction temperature is 60°C, with a reaction time of 4 hours. The ratio of ethylene oxide to methylamine is controlled at 2.9:1, the ratio of ethylene oxide to methylethanolamine at 1.9:1, and the ratio of ethylene oxide to methyldiethanolamine at 0.9:1, all slightly lower than the theoretical molar ratio. The water equivalent is preferably 5-8 eq, including the water from the methylamine aqueous solution when using an aqueous methylamine solution as a raw material.

[0140] 2. A cleaning solution composition and its preparation method are provided after CMP in IC copper manufacturing:

[0141] Example 18

[0142] 0.1% polyvinylpyrrolidone (PVP), 0.1% 2,4,7,9-tetramethyl-5-decyn-4,7-diol polyoxyethylene ether, 0.5% 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), 0.3% diethylenetriamine, 5% quaternary ammonium alkali solution (referring to the product prepared in Example 1, including 46.8% THEMAH and 11.6% MDEA), and 5% diethylene glycol butyl ether were sequentially added to 89% deionized water and stirred until a transparent solution was formed. Then, 0.01% polyether-modified polysiloxane defoamer was added and stirred until homogeneous. Finally, the pH of the solution was adjusted to 12 with 0.5% triethanolamine to obtain the cleaning solution.

[0143] Example 19

[0144] 0.01% PVP, 0.01% 2,4,7,9-tetramethyl-5-decyn-4,7-diol polyoxyethylene ether, 0.1% PBTC, 0.1% diethylenetriamine, 5% quaternary ammonium alkali solution (referring to the product prepared in Example 6, including 46.2% THEMAH and 12.2% MDEA), and 5% diethylene glycol butyl ether were sequentially added to 89% deionized water and stirred until a transparent solution was formed. Then, 0.01% polyether-modified polysiloxane defoamer was added and stirred until homogeneous. Finally, the pH of the solution was adjusted to 11.0 with 0.5% triethanolamine to obtain the cleaning solution.

[0145] Example 20

[0146] 0.01% PVP, 0.01% 2,4,7,9-tetramethyl-5-decyn-4,7-diol polyoxyethylene ether, 0.5% PBTC, 0.3% diethylenetriamine, 5% quaternary ammonium alkali solution (referring to the product prepared in Example 12, including 46.3% THEMAH and 13.8% MDEA), and 5% diethylene glycol butyl ether were sequentially added to 89 parts by weight of deionized water and stirred until a transparent solution was formed. Then, 0.02% polyether-modified polysiloxane defoamer was added and stirred until homogeneous. Finally, the pH of the solution was adjusted to 12 with 0.5% triethanolamine to obtain the cleaning solution.

[0147] Example 21

[0148] 0.1% PVP, 0.1% 2,4,7,9-tetramethyl-5-decyn-4,7-diol polyoxyethylene ether, 0.5% PBTC, 0.3% diethylenetriamine, 5% quaternary ammonium alkali solution (referring to the product prepared in Example 12, including 46.3% THEMAH and 13.8% MDEA), and 5% diethylene glycol butyl ether were sequentially added to 89% deionized water and stirred until a transparent solution was formed. Then, 0.02% polyether-modified polysiloxane defoamer was added and stirred until homogeneous. Finally, the pH of the solution was adjusted to 12 with 0.5% triethanolamine to obtain the cleaning solution.

[0149] Example 22

[0150] 0.1% PVP, 0.1% 2,4,7,9-tetramethyl-5-decyn-4,7-diol polyoxyethylene ether, 0.5% PBTC, 0.3% diethylenetriamine, 5% quaternary ammonium alkali solution (referring to the product prepared in Example 6, including 46.2% THEMAH and 12.2% MDEA), and 1% diethylene glycol butyl ether were sequentially added to 89% deionized water and stirred until a transparent solution was formed. Then, 0.02% polyether-modified polysiloxane defoamer was added and stirred until homogeneous. Finally, the pH of the solution was adjusted to 12 with 0.5% triethanolamine to obtain the cleaning solution.

[0151] Example 23

[0152] 0.1% PVP, 0.1% 2,4,7,9-tetramethyl-5-decyn-4,7-diol polyoxyethylene ether, 0.5% PBTC, 0.3% diethylenetriamine, 5% quaternary ammonium alkali solution (referring to the product prepared in Example 1, including 46.8% THEMAH and 11.6% MDEA), and 5% diethylene glycol butyl ether were sequentially added to 89% deionized water and stirred until a transparent solution was formed. Then, 0.02% polyether-modified polysiloxane defoamer was added and stirred until homogeneous. Finally, the pH of the solution was adjusted to 12.5 using 0.5% triethanolamine and 0.5% KOH solution to obtain the cleaning solution.

[0153] The cleaning solution composition provided by this invention can be used as a cleaning solution after CMP in IC copper manufacturing, or in other processes in semiconductor manufacturing.

[0154] The cleaning solution is used as follows: the cleaning solution prepared in this invention is added to the integrated ultra-cleaning unit of the polishing machine, the temperature is controlled at an appropriate temperature (20-25°C), an 854 pattern plate is placed in, the ultra-cleaning time is controlled (150-200s), and the surface cleaning effect is detected by microscope and electron microscope.

[0155] The cleaning effects of the cleaning solutions obtained in Examples 18 to 23 of this invention are shown in Table 4 below:

[0156] Table 4. Cleaning effect of the cleaning solutions obtained in Examples 18 to 23

[0157] Cleaning solution idea scratch Organic residues corrosion roughness Cleaning time acidic cleaning solution small amount none small amount small amount B B Example 18 none none none none A B Example 19 small amount none small amount none B B Example 20 small amount none serious none C C Example 21 small amount none small amount none B B Example 22 small amount none serious none A B Example 23 none none none none A A

[0158] in:

[0159] Roughness: A: 0.1-0.3nm; B: 0.3-0.5nm; C: 0.5-0.8nm;

[0160] Cleaning time: A: 180-200s; B: 150-180s; C: 100-150s.

[0161] Figures 2 to 7 This is a picture before cleaning: Figures 8 to 13 This is a diagram showing the cleaning result after cleaning with the cleaning solution composition provided in Example 23. Figure 2-13 As can be seen, after ultrawashing, the surface of the cleaning solution of the present invention is free of corrosion, with no spots or only a few spots, and the boundaries are clear and sharp, without scratches. Examples 18 and 23 show no spots, scratches, or organic residue, and exhibit good surface roughness; Example 20 shows the worst surface roughness. It is speculated that the difference in performance may be due to the fact that the quaternary ammonium alkaline solution prepared in Example 1 is more suitable as a cleaning solution after CMP in IC copper processes compared to the quaternary ammonium alkaline solutions prepared in Examples 6 and 12.

[0162] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a cleaning solution composition after CMP in IC copper manufacturing, wherein the cleaning solution composition comprises: The composition comprises: PVP 0.01%–1%, wetting agent 0.01%–0.5%, organophosphorus chelating agent 0.01%–2%, organoamine chelating agent 0.1%–5%, quaternary ammonium alkali solution 5%–10%, organic solvent 1%–15%, defoamer 0.01%–0.1%, pH adjuster 0.5%–1.0%, and the balance being water, calculated by mass percentage; the quaternary ammonium alkali solution is a composition containing tris(2-hydroxyethyl)methylammonium hydroxide directly prepared by the following method, which includes: reacting methylamine with ethylene oxide in the absence of a catalyst silica; the molar ratio of methylamine to ethylene oxide is 1:2–5; the temperature control method is: ethylene oxide is introduced at room temperature, the material temperature rises without additional heating, the reaction system temperature is controlled at 40–60°C, and the reaction time is 2–4 hours; the method also includes adding water, the molar ratio of water to methylamine is 4.6–6.

7.

2. A method for preparing a cleaning solution composition after CMP in IC copper manufacturing, wherein the cleaning solution composition comprises: The composition comprises: 0.01% PVP, 0.01% wetting agent, 0.01%–2% organophosphorus chelating agent, 0.1%–5% organic amine chelating agent, 5%–10% quaternary ammonium alkali solution, 1%–15% organic solvent, 0.01%–0.1% defoamer, 0.5%–1.0% pH adjuster, and the balance being water, calculated by mass percentage. The quaternary ammonium alkali solution is a composition containing tris(2-hydroxyethyl)methylammonium hydroxide directly prepared by the following method: reacting methylethanolamine with ethylene oxide in the absence of a catalyst (silica); the molar ratio of methylethanolamine to ethylene oxide is 1:1–5; the temperature control method is: introducing ethylene oxide at room temperature, raising the material temperature without additional heating, controlling the reaction system temperature at 40–60°C, and the reaction time at 2–4 hours; the method further includes adding water, with a molar ratio of water to methylethanolamine of 4.6–6.

7.

3. A method for preparing a cleaning solution composition after CMP in IC copper manufacturing, wherein the cleaning solution composition comprises: The composition comprises: 0.1% PVP, 0.1% wetting agent, 0.01%–2% organophosphorus chelating agent, 0.1%–5% organic amine chelating agent, 5%–10% quaternary ammonium alkali solution, 1%–15% organic solvent, 0.01%–0.1% defoamer, 0.5%–1.0% pH adjuster, and the balance being water, calculated by mass percentage. The quaternary ammonium alkali solution is a composition containing tris(2-hydroxyethyl)methylammonium hydroxide, directly prepared by the following method: reacting methyldiethanolamine with ethylene oxide in the absence of a catalyst (silica); the molar ratio of methyldiethanolamine to ethylene oxide is 2:1–5; the temperature control method is: introducing ethylene oxide at room temperature, raising the material temperature without additional heating, controlling the reaction system temperature at 40–60°C, and the reaction time at 2–4 hours; the method further includes adding water, with a molar ratio of water to methyldiethanolamine of 4.6–6.

7.

4. A method for preparing a quaternary ammonium alkali solution, characterized in that, The method includes: using one or more of methylamine, methylethanolamine, and methyldiethanolamine as raw materials, reacting them with ethylene oxide in the absence of a catalyst (silica) to obtain a quaternary ammonium alkaline solution containing tris(2-hydroxyethyl)methylammonium hydroxide; when using one of methylamine, methylethanolamine, or methyldiethanolamine as raw materials, the molar ratio of methylamine to ethylene oxide is 1:2–5; the molar ratio of methylethanolamine to ethylene oxide is 1:1–5; the molar ratio of methyldiethanolamine to ethylene oxide is 2:1–5; the temperature control method is as follows: ethylene oxide is introduced at room temperature, the material temperature rises, no additional heating is required, the temperature of the reaction system is controlled at 40–60°C, and the reaction time is 2–4 hours; the method also includes adding water, the molar ratio of water to methylamine, methylethanolamine, or methyldiethanolamine is 4.6–6.

7.

5. The method for preparing quaternary ammonium alkali solution according to claim 4, characterized in that, The methylamine is methylamine gas, methylamine aqueous solution, methylamine methanol solution, or methylamine ethanol solution; the ethylene oxide is a gas.

6. The method for preparing quaternary ammonium alkali solution according to claim 4, characterized in that, When methylamine, methylethanolamine, or methyldiethanolamine is used as a raw material, the molar ratio of methylamine to ethylene oxide is 1:2.8–3.2; the molar ratio of methylethanolamine to ethylene oxide is 1:1.8–2.2; and the molar ratio of methyldiethanolamine to ethylene oxide is 1:0.8–1.

2.

7. The method for preparing quaternary ammonium alkali solution according to claim 4, characterized in that, Specifically, the following steps are included: Step I: Add one or more of methylamine, methylethanolamine, and methyldiethanolamine, along with water, to a high-pressure reactor equipped with a stirrer and thermocouple. Turn on the stirrer, evacuate the reactor, connect a nitrogen cylinder to replace the air inside the reactor with nitrogen, and seal the reactor. Step II: Slowly add ethylene oxide at room temperature. The reaction is exothermic, and the material temperature gradually rises. Control the reaction system temperature to 40–60℃ by controlling the ethylene oxide addition rate and the cooling circulating water rate. Control the ethylene oxide addition rate to avoid material temperature fluctuations in the reactor exceeding 5℃, and control the reactor pressure to not exceed 0.5MPa. Step III: After the ethylene oxide is fed in, continue the reaction for 2–4 hours with stirring; Step IV: Stop the heat preservation, stir and bubble with nitrogen for 0.1–40 hours, then discharge to obtain a quaternary ammonium alkaline solution containing tris(2-hydroxyethyl)methylammonium hydroxide.

8. The method for preparing quaternary ammonium alkali solution according to any one of claims 4-7, characterized in that, Add the additive during feeding or after discharging, and stir evenly; the additive is selected from one or more of phenothiazine, hydroquinone, 4-methoxyphenol, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-p-methylphenol, ethylenediamine, hydroxyethyl ethylenediamine, and diethyl hydroxylamine.

9. A cleaning solution composition after CMP in IC copper manufacturing, characterized in that, The components are as follows: surfactant 0.01%–1%, wetting agent 0.01%–0.5%, organophosphorus chelating agent 0.01%–2%, organoamine chelating agent 0.1%–5%, quaternary ammonium alkali solution 5%–10%, organic solvent 1%–15%, defoamer 0.01%–0.1%, pH adjuster 0.5%–1.0%, and the balance is water, calculated by mass percentage; the quaternary ammonium alkali solution is a product directly obtained by the preparation method of quaternary ammonium alkali solution according to any one of claims 4–8.

10. The composition according to claim 9, characterized in that, The surfactant is selected from one or more of polyvinylpyrrolidone and fatty alcohol polyoxyethylene ether; the wetting agent is acetylenol polyether; the organophosphorus chelating agent is selected from one or more of 2-phosphonobutane-1,2,4-tricarboxylic acid, aminotrimethylphosphonic acid, ethylenediaminetetramethylphosphonic acid, diethylenetriaminepentamethylphosphonic acid, polyaminopolyether-based methylenephosphonic acid, and hydroxyethylidene diphosphonic acid; the organoamine chelating agent is selected from diethylenetriamine, triethylenetetraamine, and tetraethylenepentamine; the organic solvent is selected from one or more of propylene glycol methyl ether, propylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, and diethylene glycol butyl ether; the defoamer is a modified polysiloxane defoamer; and the pH adjuster is selected from ethanolamine, diethanolamine, and triethanolamine.

11. The application of the product directly obtained by the method for preparing quaternary ammonium alkali solution according to any one of claims 4–8 in the preparation of cleaning solution after CMP in IC copper processing.

12. The use of the composition of claim 9 or 10 in the preparation of a cleaning solution after CMP in IC copper processing.

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